SpotOn ground control application

The SpotOn ground control application is an in-progress project that is built on top of chobitsfan's MiniGroundControl, which contains lightweight functionality for mavlink communcation over usb serial antennas. It is tailored to be a UAV surveying tool which allows users to select locations on an integrated map and direct a quadcopter with a laser-gimbal attachment over those spots.

This project is intended to be a more polished and practical version of the proof-of-concept we created in the Fall 2023 semester.

This project also uses osmdroid to integrate Open Street Map.

Features

• Added buttons and functionality for some important controls:
  1. Set UAV to STABALIZE, GUIDED, or LAND mode.
  2. Arm/Disarm UAV throttle.
  3. Takeoff.
  4. Send a global waypoint.
• Integrated a osmdroid map view
  1. Display current location of UAV on map as an icon.
  2. Extract the 2D global coordinates of a point that the user taps within the map view.
  3. Save the map tiles for a specified area to local memory so that they can be accessed offline.

Usage

Equipment Needed

• Quadcopter equipped with ArduPilot flight controller, GPS antenna, and telemetry radio.
• Serial USB telemetry radio
• Android device with the SpotOnMiniGroundControl app installed

Setup and Connection

1. Connect the serial USB antenna to your Android device. This antenna will facilitate communication between your mobile device and the UAV.
2. Open the SpotOnMiniGroundControl application on your Android device. The app should automatically detect the serial USB antenna and ask for permission to use the device.
3. Turn on the UAV. The app should automatically establish a connection and display the UAV's information within the app.

Takeoff and land

1. When the UAV is connected and has completed pre-flight calibration, press "set mode GUIDED".
2. In guided mode press "force arm" to arm the throttle.
3. When the motors begin spinning, press "takeoff" and the UAV will take off to 3 meters.
4. If you press land, the UAV will descend and land from wherever it is currently flying.

Structure

Java source files

• com.chobitsfan.minigcs
  • ArduCopter: Handles specific functionalities related to the ArduCopter, an implementation detail for ArduPilot based drones.
  • MainActivity: The main entry point of the application where the UI components are initialized and user interactions are managed. Most of the control logic is here.
  • MyAppConfig: Configuration class for managing global application settings.
  • MyMavlinkWork: Manages MAVLink communications, contains all the builders for all the messages.
    • All of the setMode() functions work as expected with the simulated and real UAV.
    • setGPSOrigin() is a function we wrote because we were not sure if we need to set the GPS origin before the UAV will accept a waypoint. It does not look like we need to.
    • sendGlobalWaypoint(lat, lon, alt) creates the message to send the MAV_CMD_NAV_WAYPOINT to the UAV with a specified altitude and 2D GPS coordinate. In the simulations we tried, this message was unsupported by GUIDED mode. However, when we tested on the physical quadcopter it appeared to accept the waypoint; After pressing the "send waypoint" button while the drone was hovering about 2 meters off the ground, it began rapidly heading towards the coordinate but then crashed into the ground.
    • takeoff() and land() messages work as expected in simulation and real-life. The drone has to be armed in GUIDED mode to accept the takeoff message, however it can accept land() in any mode.
  • MyUSBSerialListener: Handles USB serial communication for real-time data exchange with the UAV.

Future work

We finished the Spring 2024 semester with an application that can connect to the UAV, collect and display information about it's current state, and send some basic messages to control the UAV's behavior:

• Connecting to the UAV through an android device and USB telemetry radio.
• Taking off and landing.
• Showing current UAV location on map.

However there are still several components that need to be added before this application is useful:

• Precisely select a point of interest on the map view and place a pin icon to mark that spot.
• Direct the UAV to each selected waypoint safely and precisely.
• Loiter at each waypoint until the user would like the UAV to go to the next point.
• Control the laser gimbal attachment through the app.